CHAPTER ONE

INTRODUCTION

1.1 Background of the Study

In the semi-arid region of north-eastern Nigeria, cowpea farmers can improve their farmland using materials that are often readily available around them, such as millet and sorghum stalks, dry grass, crop husks and fallen leaves. When these materials are spread over the soil surface, they are referred to as mulch. One of the major benefits of mulching in dry environments is its ability to reduce moisture loss from the soil. Cowpea is cultivated by a large proportion of farmers in the semi-arid north-east. However, Ekle et al. (2023) observed that cowpea productivity in the region has declined over the years. This decline is a major concern because many households depend on the crop for both food and income.

Research conducted in Maiduguri has shown that mulching can influence cowpea production. Ekle et al. (2023) investigated the effects of tillage practices and different rates of millet residue mulch on cowpea at the Teaching and Research Farm of the University of Maiduguri. Their findings showed that the treatments significantly affected all the yield parameters examined. Under no-till conditions, grain yield and its components improved as the quantity of millet residue increased. The study also identified differences in water-use efficiency among the treatments. In another study involving cereals cultivated in Maiduguri, Eze et al. (2014) examined the application of rice husk mulch on sorghum and millet grown on sandy loam soil. At one of the study locations, applying mulch at 10 and 15 tonnes per hectare produced grain yields that were 14.3% and 15.3% higher, respectively, than the yield obtained without mulch. Stover yield also increased with higher mulch application rates at both locations. However, the harvest index at the 15 tonnes per hectare rate was lower than those recorded at 0 and 10 tonnes per hectare at one location. This suggests that increasing the quantity of mulch does not necessarily improve every aspect of crop performance.

Studies conducted across the wider Sahel region also indicate that the type of mulching material can influence crop performance. Ibrahim et al. (2015) compared the effects of Acacia tumida prunings, millet residues and manure used as mulch on millet production in Niger. They reported grain yield increases of 51% for manure, 46% for Acacia mulch and 36% for millet residue mulch compared with the unmulched treatment. The researchers also identified the limited availability of organic soil amendments as a major challenge in the Sahel. This indicates that the availability of materials for mulching can be a serious constraint in areas where vegetation and farm residues are limited. Therefore, cowpea farmers in Maiduguri must consider not only whether to use mulch but also which materials are available and suitable for their farms and surrounding communities.

The quantity of mulch applied is another important factor that may influence crop growth and yield. Adebimpe et al. (2017) investigated the effects of elephant grass mulching on cowpea production in southern Nigeria. Their findings showed that mulching significantly improved soil moisture content. However, the study also found that growth and yield characteristics improved at 30% mulch cover but declined when the coverage increased to 60% and 90%. This indicates that excessive mulching may not necessarily produce better results. Farmers who apply large quantities of crop residues in an attempt to conserve soil moisture may not always achieve the expected improvement in crop performance.

Although the benefits of mulching have been examined in previous studies, information about farmers' actual mulching practices remains limited. In Oyo State, Akinnagbe and John (2023) surveyed 200 arable crop farmers and found that all the respondents practised mulching, while 91% reported using it frequently. This made mulching one of the most commonly adopted soil conservation practices among the farmers. However, the study identified population pressure on farmland and access to financial resources as important factors affecting the effective use of conservation practices. Similarly, Danmusa and Umar (2024), in their study of cowpea production in Katsina State, found that labour was a significant factor influencing cowpea output. Since collecting, transporting and spreading mulch require additional labour, these activities may increase farmers' production costs and workload. However, it is not clear whether cowpea farmers in the semi-arid north-east experience similar challenges or consider mulching sufficiently beneficial to justify the additional effort.

Existing research conducted in Maiduguri has mainly focused on experimental plots established on university farms, where researchers determine the type, quantity and timing of mulch application. Farmers operate under different conditions and must make these decisions based on the materials available to them, the alternative uses of crop residues, the labour required and their observations of crop performance. They also assess whether the benefits of mulching justify the time and resources invested in the practice. Information about farmers' experiences, including the growth and yield they report when using different mulching materials or when they do not mulch, is therefore important. However, the studies reviewed for this research have not adequately documented these experiences among cowpea farmers in Maiduguri. This study seeks to obtain such information through a questionnaire-based survey.

1.2 Statement of the Problem

Cowpea production in the semi-arid north-east has experienced a decline in productivity over the years (Ekle et al., 2023). One of the major challenges affecting crop production in this environment is limited soil moisture. Mulching is considered a useful practice for conserving soil moisture, and experimental research conducted at the University of Maiduguri has shown that applying millet residue mulch can improve cowpea yield (Ekle et al., 2023). However, previous studies have also demonstrated that the performance of mulch depends on several factors, including the type of material used (Ibrahim et al., 2015), the quantity applied (Adebimpe et al., 2017; Eze et al., 2014) and the tillage method adopted (Ekle et al., 2023). Therefore, the benefits of mulching cannot be assumed to be the same under all farming conditions.

There is insufficient information on the specific mulching materials used by cowpea farmers in Maiduguri, the quantities they apply, the stages of crop development at which they apply them and the reasons behind their choices. It is also unclear how farmers assess the growth and yield of cowpea under different mulching materials compared with cultivation without mulch. Furthermore, the challenges that prevent farmers from adopting or increasing the use of mulching materials have not been adequately established. The limited availability of organic materials in the Sahel (Ibrahim et al., 2015) and the additional labour required for mulching activities (Danmusa & Umar, 2024) suggest that the practice may involve challenges that are not fully reflected in experimental studies. However, there is limited local evidence to establish how these factors affect farmers in Maiduguri.

The absence of this information creates difficulties for agricultural extension workers, farmers and researchers. Extension recommendations on mulching in Borno State may depend mainly on experimental findings and general agricultural principles without adequately considering the materials, financial resources and labour available to local farmers. Farmers who are interested in adopting mulching may also lack information about the experiences of others who use different materials. In addition, researchers planning future experiments may not have sufficient information about the materials and application rates that farmers can realistically use under normal farming conditions.

The problem addressed by this study is therefore the lack of adequate farmer-level information in Maiduguri Metropolitan Area on the types of mulching materials used by cowpea farmers, the growth and yield they report under the different mulching practices, and the constraints affecting the adoption and use of mulch.

1.3 Objectives of the Study

The main objective of this study is to assess the effects of different mulching materials on the growth and yield of cowpea as reported by farmers in Maiduguri Metropolitan Area.

The specific objectives are to:

1. Describe the socio-economic and farm characteristics of cowpea farmers in the study area.

2. Identify the types of mulching materials used by farmers, the quantities applied and the stages of crop development at which they are applied.

3. Examine the growth and yield of cowpea as reported by farmers using different mulching materials and those who do not use mulch.

4. Determine whether the yield reported by farmers differs across the different mulching materials and identify the constraints affecting the use of mulch.

1.4 Research Questions

The study will be guided by the following research questions:

1. What types of mulching materials do cowpea farmers in Maiduguri use, in what quantities and at what stages of crop development are they applied?

2. What growth and yield outcomes do farmers report when using different mulching materials compared with farming without mulch?

3. Is there a significant difference in the yield reported by farmers using different mulching materials?

4. What are the major constraints affecting the use of mulch among cowpea farmers?

1.5 Research Hypotheses

The following null hypotheses will be tested at the 5% level of significance:

H01: There is no significant difference between the cowpea yield reported by farmers who use mulch and those who do not use mulch.

H02: There is no significant difference in the cowpea yield reported by farmers using different types of mulching materials.

H03: There is no significant relationship between the socio-economic characteristics of farmers, including age, sex, educational level, farm size and farming experience, and their use of mulch.

1.6 Significance of the Study

The findings of this study will be useful to cowpea farmers in Maiduguri because they will provide information on the mulching materials used by other farmers and the growth and yield outcomes they report. The study will also highlight the labour and financial requirements associated with mulching. Farmers who have not adopted the practice may use the findings to understand the experiences of those who already use mulch, while existing users may compare their choices and practices with those of other farmers.

Agricultural extension workers in the Borno State Agricultural Development Programme and relevant research institutions will also benefit from the findings. The information may assist them in recommending suitable mulching materials and application quantities based on farmers' experiences and available resources. It may also help them determine whether existing mulching practices should be encouraged, adjusted or supported through programmes that improve access to organic materials.

The study will further provide useful information to researchers at the University of Maiduguri and other agricultural institutions. The findings will offer farmer-level evidence that can guide the design of future field experiments under conditions that reflect the realities of local farming communities.

More generally, the research will contribute to the limited information available on farmers' mulching practices in north-eastern Nigeria. This is particularly important because soil moisture is a major factor affecting agricultural production in the region, while cowpea productivity has been reported to be declining (Ekle et al., 2023).

1.7 Scope and Delimitation of the Study

The study is limited to cowpea farmers in Maiduguri Metropolitan Area of Borno State who cultivated cowpea during the most recent cropping season.

The research will adopt a cross-sectional survey design and use a structured questionnaire to collect information from the respondents. Field observations will also be conducted on selected farms where access and other conditions permit.

The study focuses on the types of mulching materials used by farmers, the quantities applied, the timing of application, the growth and yield reported under each mulching practice, and the constraints affecting the use of mulch.

The study excludes plastic film mulching, comparisons of tillage methods, soil laboratory analysis, comparisons of cowpea varieties and the production of crops other than cowpea.

1.8 Limitations of the Study

The study may be affected by the following limitations:

1. Self-reported information: Information on cowpea growth and yield will depend mainly on farmers' responses. Some respondents may not remember or accurately estimate their harvest quantities and crop performance.

2. Inability to establish cause and effect: Farmers who use mulch may also adopt other improved farm management practices. Therefore, differences in reported yield cannot be attributed to mulching alone because other production factors may also influence the results.

3. Difficulty in measuring mulch quantities: Most farmers may not use standard measurements when applying mulch. This may make it difficult to compare application quantities accurately. In addition, the quality and composition of the different mulching materials may vary.

4. Security and resource constraints: Security challenges, limited research time and inadequate financial resources may restrict access to some farming communities and reduce the number of respondents that can be included in the study.

1.9 Definition of Terms

Mulch: Any material spread over the soil surface around crop plants to conserve soil moisture, regulate soil temperature or reduce weed growth.

Mulching Materials: Organic materials used to cover the soil surface, including crop stalks, grasses, husks and fallen leaves, as identified by the farmers.

Growth: The development of cowpea plants, assessed through farmers' reports of plant vigour, height and ground coverage.

Yield: The quantity of cowpea grain harvested from a particular area of farmland, as reported by the farmer.

Semi-arid: A climatic condition characterised by relatively low and unreliable rainfall, which often results in insufficient soil moisture for crop growth during much of the year.

REFERENCES

Adebimpe, O., et al. (2017). Cowpea response to compaction and mulching on a sloping loamy sand soil in Southern Nigeria. Agricultural Engineering International: CIGR Journal, 19(1).

Akinnagbe, O. M., & John, A. M. (2023). Use of conservation practices among arable crop farmers in Oyo State, Nigeria. Journal of Agricultural Extension, 27(2). https://doi.org/10.4314/jae.v27i2.11

Danmusa, A. H., & Umar, A. S. S. (2024). Determinants and profitability of cowpea production in Safana Local Government Area, Katsina State, Nigeria. Sahel Journal of Life Sciences FUDMA, 2(1). https://doi.org/10.33003/sajols-2024-0201-029

Ekle, A. E., Ali, E., Iorlaha, V. A., Yisa, K. M., Kundet, A., Silas, Y. G., Kolo, P. N., & Ngala, A. L. (2023). Effect of tillage and millet residue mulch rates on water use efficiency of cowpea [Vigna unguiculata (L.) Walp] in Maiduguri, Nigeria. Adamawa State University Journal of Scientific Research, 11(1).

Eze, P. C., Alhassan, A. B., Kwari, S. J., Dada, Y. M., Tsado, P. A., & Lawan, A. N. (2014). Yield of sorghum and millet as affected by rice husk mulch on a sandy loam soil in Maiduguri, semi-arid north-east Nigeria. Nigerian Journal of Soil Science.

Ibrahim, A., Abaidoo, R. C., Fatondji, D., & Opoku, A. (2015). Integrated use of fertilizer micro-dosing and Acacia tumida mulching increases millet yield and water use efficiency in Sahelian semi-arid environment. Nutrient Cycling in Agroecosystems, 103(3).